JPH07293256A - Intake device of internal combustion engine - Google Patents

Abstract

PURPOSE:To provide the optimum intake flow according to load requirement over the whole running area while improving an acceleration controlling property by using a swirl controlling valve for traction control in common. CONSTITUTION:A swirl controlling valve 5 to open an intake path 6 with the relative small opening in the low and medium load areas of an engine and fully open the the intake path in the high load area is provided in the intake path 6 downstream of a throttle valve to reduce the opening of the swirl controlling valve 5 for restraining the output torque of the engine in abrupt acceleration. The swirl controlling valve 5 is opened and closed according to the rotational frequency of the engine by a motor 15 in the low and medium load areas of the engine, and intake passes through the swirl controlling valve 5 to generate a proper swirl in a combustion chamber. When the high load area is reached, the swirl controlling valve 5 is fully opened to supply intake in multiple layers to the combustion chamber and improve the efficiency of filling intake. In the abrupt acceleration, the function of the swirl control is stopped and the opening of the swirl controlling valve 5 is controlled to set the output torque to the best value irrespective of the accelerator opening and prevent the slip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for an internal combustion engine, and more particularly to an intake system for an internal combustion engine having a swirl control valve in an intake passage downstream of a throttle valve.

[0002]

2. Description of the Related Art Conventionally, in an internal combustion engine, a swirl is generated in the combustion chamber to improve combustion efficiency in a low / medium load operating range such as idling with a small intake amount, while in a high load operating range where the intake amount is large, A method of suppressing swirl to improve intake charging efficiency is known. That is, the swirl control valve provided downstream of the throttle valve starts to open later than the throttle valve so that the intake passage is throttled by the swirl control valve in the low / medium load region of the engine, while the swirl control valve is opened in the high load region. Is fully opened to obtain the optimum swirl for each load range.

In Japanese Patent Laid-Open No. 63-248919, the intake passage is closed in the low load region of the engine.
1st which has a notch of a comparatively small area which opens in a high load area
Of the first swirl control valve and a second swirl control valve located upstream of the first control valve and closed in the low / medium load region of the engine and opened in the high load region and having a notch with a relatively large area are connected in series with each other. The provided one is shown.

On the other hand, as an acceleration control device for properly controlling the slip of the drive wheels during vehicle acceleration, an auxiliary throttle valve is provided downstream of the throttle valve of the intake device to control the output torque of the engine during sudden acceleration. A method of performing so-called traction control is disclosed in, for example, Japanese Patent Laid-Open No. 322964/1988.

By the way, when arranging a plurality of various control valves other than the throttle valve in the intake passage, there are great restrictions on the installation location.
Therefore, it is unavoidable to adopt only a specific control valve whose application is limited.

[0006]

In order to solve the above problems, the present invention uses the swirl control valve also for traction control to obtain the optimum intake flow according to the load condition over the entire operating range. In addition, it is an object of the present invention to provide an intake device having excellent acceleration control characteristics.

[0007]

A swirl control valve is provided in the intake passage downstream of the throttle valve to open the intake passage at a relatively small opening in the low / medium load range of the engine and to fully open it in the high load range. During rapid acceleration, the opening degree of the swirl control valve is reduced to suppress the output torque of the engine.

[0008]

In this structure, the swirl control valve is opened / closed in accordance with the engine speed in the low / medium load range of the engine.
Intake air passes through the swirl control valve and enters the appropriate swirl chamber.
To generate When the high load region is reached, the swirl control valve is fully opened, a large amount of intake air is supplied to the combustion chamber, and intake charge efficiency is improved. At the time of sudden acceleration, the swirl control function is stopped, the state of the wheel speed is detected, and the opening of the swirl control valve is controlled so that the output torque becomes the best value regardless of the accelerator opening. Hold down the slip.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall configuration of an embodiment of the present invention in a multi-cylinder internal combustion engine, and FIG. 2 is a bottom view thereof.
A casing 7 is mounted between the intake pipe 1 and a cylinder head having an intake port communicating with the combustion chamber, and the intake pipe 1, the casing 7 and the cylinder head form an intake passage 6. A throttle valve 10 is provided in the intake pipe 1, and a swirl control valve 5 rotatable about a shaft 11 is provided in the casing 7. Swirl control valve 5
Has a notch 5C on one side of the shaft 11, and the wall surface of the corresponding casing 7 is vertical. Further, the wall surface of the casing 7 corresponding to the non-notched side 5A of the swirl control valve 5 is closed so as to block the intake passage 6 from the full opening of the swirl control valve to the opening of 40 degrees. It is a curved surface portion 7A along the locus of the tip. The swirl control valve 5 is a low
While it has a predetermined opening in the medium load range according to the engine speed,
Fully open in high load range.

The opening degree of the throttle valve 10, that is, the depression amount of the accelerator pedal 12 is detected by an accelerator sensor 13 and input to a control unit 14. Further, the engine speed N is detected by the engine speed sensor 8 and input to the control unit 14. The control unit 14 includes an operation mode determination unit 140, a swirl control unit 141, and a traction control unit 142, calculates the opening degree of the swirl control valve 5 based on a predetermined characteristic, and the shaft 11 Controls the rotation of the motor 15 connected to. The control unit 14 has a CPU 5 as shown in FIG.
2, ROM 54, RAM 56, bus 58 and the like. Further, the acceleration sensor 13, the swirl sensor 16, the hydraulic pressure switch 24, the left and right front wheel speed sensors 26 and 28, and the rear wheel speed sensor 30 are connected via the input unit 60. On the other hand, the swirl control mode is output via the output unit 62.
The motor 15, the electromagnetic directional control valve 17, the electromagnetic flow control valve 18, and the pump motor 19 are connected.

The ROM 54 stores various control programs and a swirl control table giving control characteristics of the swirl control valve.

The swirl control valve 5, the swirl control mode
The traction control unit 142 includes a brake controller 15 and a hydraulic brake.
Constitutes the actuator of.

Next, the operation of the intake device having the above structure will be described. As shown in FIG. 4, the driving mode determination unit 140
Determines whether or not it is in a rapid acceleration state based on the output of the accelerator sensor 13, and normally performs swirl control and traction control during rapid acceleration. That is, while the key switch of the vehicle is in the ON state, the control unit 14 is
The control routine shown in FIG. 4 is used for a certain short time, for example, 5 msec.
Execute every time. First, in step 402, the driving mode is detected and it is determined whether or not the amount of change in depression of the accelerator pedal 12 is large. If the amount of change in the depression of the accelerator pedal 12 is small, the vehicle is not in the acceleration mode, so swirl control is performed (step 40).

When the amount of change in the depression of the accelerator pedal 12 is large and the slip of the wheel is detected, the traction control is performed (404 to 408).

The swirl control unit 141 includes a throttle valve 10 that is fully closed or close to it, and the engine has a low speed including idling.
When in the medium speed, low load range, the opening degree of the swirl control valve 5 is
The control is performed so that the characteristics shown in A of FIG. 5 are obtained. That is, the opening degree changes in the shaded area indicated by A according to the engine speed and load. When the swirl control valve 5 is fully closed, the intake air is supplied to the swirl control valve 5 at a relatively small area 5C.
To the intake port and then into the combustion chamber. This intake air flows along the wall surface of the intake port, and a strong swirl optimal for the low load region is generated in the combustion chamber.

Next, when the throttle valve 11 is gradually opened from this state and the load of the engine is increased to reach a low / medium-speed high load range, the opening degree of the swirl control valve 5 is instructed by the swirl control section 141. It becomes a little big. The opening ratio of the intake passage 6 continuously increases or decreases according to the opening degree of the swirl control valve. As a result, a gap 5D is formed between the left side of the swirl control valve 5 and the casing. The intake air flows into the combustion chamber through the gap (5C + 5D) having a relatively large area. This intake is greater than that at low load, and optimal swirl is generated in the medium load range.

When the throttle valve 11 is further opened from this state and the engine load increases to reach the high speed high load range, the characteristics shown in FIG. 5B, that is, the swirl control valve 5 is instructed by the instruction of the swirl control unit 141. Fully open. Along with this, a large amount of intake air is supplied to the combustion chamber, and the intake air charge ratio becomes sufficient.

Next, the traction control section 142 controls the opening degree of the swirl control valve 5 at the time of sudden acceleration. That is, when the accelerator sensor 12 detects a state in which the depression amount of the accelerator pedal 12 suddenly increases, the traction control unit 142 gives priority to the control of the swirl control unit 141 and provides an output torque suitable for slip control. Control of the opening of the swirl control valve 5 and
Control is performed.

As described above, according to the present invention, the swirl control valve is continuously opened / closed in the low / medium load range of the engine in accordance with the engine speed, and the intake air is burned through the swirl control valve. Generate a suitable swirl in the room. When the high load region is reached, the swirl control valve is fully opened, a large amount of intake air is supplied to the combustion chamber, and intake charge efficiency is improved. On the other hand, at the time of sudden acceleration, the swirl control function is stopped, and the opening of the swirl control valve is controlled so that the output torque becomes the best value regardless of the accelerator opening, and the vehicle slip is suppressed.

[0020]

According to the present invention, since the opening ratio of the intake passage in the low / medium load region of the engine is continuously variable by the swirl control valve, the swirl control valve can also be used for traction control. Therefore, a plurality of functions can be realized without complicating the structure of the intake passage.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of an intake device according to a first embodiment of the present invention.

FIG. 2 is a bottom view of a main part of the intake device of FIG.

FIG. 3 is a diagram showing an example of the control unit shown in FIG.

FIG. 4 is a diagram showing a control flow of a swirl control valve.

FIG. 5 is a diagram showing a swirl control characteristic of the swirl control valve.

[Explanation of reference numerals] 5 ... swirl control valve, 12 ... accelerator pedal, 15 ... motor, 140 ... driving mode determination unit, 141 ... swirl control unit, 142 ... traction control unit

Claims (6)

[Claims] 1. A swirl control valve is provided in the intake passage downstream of the throttle valve so that the swirl control valve is opened at a relatively small opening in the low and medium load regions of the engine and is fully opened in the high load region. In addition to the above control, when the vehicle is suddenly accelerated, the opening degree of the swirl control valve is controlled according to the wheel speed to suppress the output torque of the engine. 2. The swirl control valve is case-mounted via a shaft, and has a notch on one side of the shaft and no notch on the other side. The inner wall surface of the casing on the side having the notch is a vertical surface, and the inner wall surface of the casing on the side without the notch is along the locus of the tip end surface of the swirl control valve. The intake device for an internal combustion engine according to claim 1, wherein the intake device has a concave curved surface. 3. The concave curved surface is configured so as to shield the non-notched side of the intake passage by the swirl control valve from the time when the swirl control valve is fully closed to a predetermined opening degree. The intake system for an internal combustion engine according to claim 2, wherein: 4. The intake system for an internal combustion engine according to claim 2, wherein the predetermined opening degree is 40 degrees. 5. The swirl control valve is continuously opened / closed in a low / medium load region of the engine to continuously control the opening ratio of the intake passage and is fully opened in a high load region. An intake system for an internal combustion engine according to claim 1 or 2, further comprising a swirl control unit. 6. The intake system for an internal combustion engine according to claim 4, further comprising a motor for opening and closing the swirl control valve according to an output of the swirl control unit.